1. Field of the Invention
The present invention relates to a cryogenic tank for a space launcher and a space launcher comprising such a tank.
2. Related Art
In the ballistic phase, or during the transitional satellite station acquisition phases, the propellants may wet all the walls of their tank. This leads to an extremely significant evaporation of the cryogenic liquid in the tank and a strong cooling of the gaseous dome situated above the liquid part of the tank. Solutions to this problem are known for non-cryogenic propellants (called storable propellants). These solutions are based on the capillary forces. The propellants are retained in the bottom part of the tank (close to the liquid outlet) by capillarity. For the cryogenic fluids, these solutions are difficult to apply because of thermo-capillary instabilities and possible evaporations close to the capillary systems resulting in drying of the systems and therefore a loss of efficiency.
Preferably according to the invention, to resolve this problem, an intermediate partition is provided in the storage volume so as, on the one hand, to allow for the flow of liquid by gravity from the top volume of the tank to the bottom volume of the tank via one of the central openings formed in the intermediate partition and, on the other hand, to prevent the rise of the liquid from the bottom volume to the top volume via the central opening or openings under the action of acceleration forces.
This type of solution is overall satisfactory. However, when filling the tank or in certain flight situations, the vaporization of the cryogenic liquid (notably against the internal face of the storage volume) may create vapor which is held captive under the abovementioned partition. This captive vapor under the partition may adversely affect the operating characteristics of the tank in the flight phase.
To resolve this problem, the addition of orifices to the partition would make it possible to evacuate the vapor bubbles, but this solution would result in liquid leaks toward the top of the tank in roll phases. These liquid leaks must be avoided to limit the wetting of the walls of the tank and excessive evaporations.
One aim of the present invention is to mitigate all or some of the drawbacks of the prior art mentioned above.